Industry Segment Information (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Fee revenue and other income:
Fee income from customers		$ 28,262	$ 26,435	$ 82,647	$ 77,449
Interest income	[1]	14,177	12,778	41,472	36,891
Interest expense		1,392	1,029	3,987	2,502
Intersegment income (expense)
Tax-equivalized pre-tax income	[1]	10,484	9,654	30,887	29,663
Goodwill		15,894	12,569	15,894	12,569	$ 12,569
Other intangible assets, net		3,170	1,664	3,170	1,664
Total assets		1,781,010	1,678,247	1,781,010	1,678,247	$ 1,695,176
Average funding sources		1,292,998	1,200,861	$ 1,251,199	$ 1,203,898
Tax-equivalent basis tax rate				21.00%	21.00%
Tax-equivalent adjustment		511	564	$ 1,583	$ 1,875
Information Services [Member]
Fee revenue and other income:
Fee income from customers		28,026	26,263	82,049	76,397
Interest income	[1]	6,760	6,446	19,273	18,621
Interest expense
Intersegment income (expense)
Tax-equivalized pre-tax income	[1]	7,619	7,269	21,997	21,394
Goodwill		15,758	12,433	15,758	12,433
Other intangible assets, net		3,170	1,664	3,170	1,664
Total assets		908,946	903,055	908,946	903,055
Average funding sources		704,772	650,267	667,741	637,508
Banking Services [Member]
Fee revenue and other income:
Fee income from customers		257	253	1,040	947
Interest income	[1]	7,930	6,661	23,082	20,351
Interest expense		1,392	1,029	3,987	2,502
Intersegment income (expense)		533	467	1,587	1,415
Tax-equivalized pre-tax income	[1]	3,399	2,796	10,214	10,245
Goodwill		136	136	136	136
Other intangible assets, net
Total assets		862,142	847,673	862,142	847,673
Average funding sources		588,226	550,594	583,458	566,390
Corporate Eliminations and Other [Member]
Fee revenue and other income:
Fee income from customers		(21)	(81)	(442)	105
Interest income	[1]	(513)	(329)	(883)	(2,081)
Interest expense
Intersegment income (expense)		(533)	(467)	(1,587)	(1,415)
Tax-equivalized pre-tax income	[1]	(534)	(411)	(1,324)	(1,976)
Goodwill
Other intangible assets, net
Total assets		9,922	(72,481)	$ 9,922	(72,481)
Average funding sources

[1] Presented on a tax-equivalent basis assuming a tax rate of % for both 2019 and 2018. The tax-equivalent adjustment was approximately $ for the Three Months Ended 2019 and 2018, respectively, and $ for the Nine Months Ended 2019 and 2018, respectively.